Article coating apparatus



Oct.

i6, 1945. E. .1. sHAw ARTICLE COATING APPARATUS Filed Nov. l2, 1945 2Sheets-Sheet 1 wrm...

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Oct. 16, 1945. E. J. SHAW ARTICLE COATING APPARATUS 2 Sheets-Sheet 2Filed Nov. l2, 1943 INVENTOR. EJ. SHAW ao BY ATTORNEY gerentes ocr. 1c,i945 ARTICLE COATING APPARATUS Everett J. Shaw, Western Springs, Ill.,assigner to Western Electric Company, Incorporated, New York, N. Y., facorporation of New York Application November 12, 1943, Serial No.509,979

13 Claims. '(Cl. 91-41) This invention relates to article coatingapparatus vand more particularly to an apparatus for applying a carboncoating to either end of a cylindrical body, such as a resistor.

In the manufacture of certain types of carbon resistors, it is sometimesthe practice to apply a coating of conducting material to either end ofthe resistor to insure good electrical contact between the resistor andits terminals. Such a coating may be applied by dipping, but ispreferably applied by brushing since brushing produces a more uniformand adherent coating.

An object of the present invention is to provide an eiiicient andeffective apparatus for coating the ends of cylindrical bodies such asresistors.

In accordance with one embodiment of this invention, an apparatus may beprovided comprisving a plurality of radially disposed brushes' mountedon the upper end of a hollow rotatable shaft from which coating materialis supplied and maintained at a constant level with respect to thebrushes by a gear pump positioned inv a tank. The unused coatingmaterial flows back to the tank and is recirculated through the shaft bythe pump.

Other objects and advantages of the present invention will be apparentfrom the following detailed description taken in conjunction with thedrawings, wherein Fig. 1 is a plan view of the apparatus;

Fig. 2 is a detailed plan view showing the brushes and their supportingsection;

Fig. 3 is a vertical sectional view along the line 3--3 of Fig. 1; and

Fig. 4 is a vertical sectional view along the line 4 4 of Fig. 1, takenat right angles to the line in Fig. 3.

Referring now to the drawings, and particularly to Figs. 1 and 3, itwill be seen that this coating apparatus comprises a heavy rectangularbase plate I Il on which is mounted a housing block I I, the block beingiixed to the plate by a number of bolts I2 which are mounted in theplate and threadediy engage the housing block, A large trilateral cavityI3 is formed within the housing block II in the left portion thereof, asviewed in Figs. 1 and 3, and serves as a tank from which coatingcompound may be pumped by a gear pump comprising two intermeshing spurgears I4 and I5, portions of the peripheries of which are disposedwithin the cavity I3 and at the base thereof. Access to the cavity I3 isprovided by a circular aperturev IB formed in the portion of the housingblock immediately above the cavity. A

cover plate I'I. may be placed over the cavity I3 5 and held in place bya thumb nut 20 which threadedly engages a vertically disposed shaft 2l,the lower end of which is mounted on the base plate Ill.

The spur gear I@ is mounted on the lower end of a vertically disposedhollow shaft 22, journalled in a bearing 23, formed in the housing blockII, the gears I4 being driven by the second spur gear I5 which is fixedto the lower end of a shaft 24. As may be seen in Fig. 4, the shaft 24is journalled in a bearing 25 formed in the housing block II. The lowerend of a driving or power shaft 26 extends into a suitable aperture 2lformed in the upper portion of the shaft 2i and is retained therein by aset screw 28.` This drive shaft may be rotated by any suitable means,such as a small electric motor.

The gears Is and I5 cooperatively serve as a gear pump, the gear IBrotating in counter-clockwise direction, while the gear I5 rotates in aclockwise direction, as viewed in Fig. 1. As the gears are rotated, thecoating compound in the reservoir I3 flows between the teeth of thegears I -moving through the reservoir I3 and the coating compound iscarried around to the point at which the gears mesh. Meshing of thegears causes the coating compound to be squeezed out from the teeththereof and forced into one end of a channel 30 formed in the housingblock. This end of the channel, as may be seen in Fig. l, is positionedslightly ahead of the point at which the gears mesh. Suiiicient pressureis developed on the coating compound at this point to force the compoundthrough the channel and to the other end thereof which4 communicateswith the lower end of the hollow shaft 22. The coating compound isforced vertically through the shaft and into contact with a number ofbrushes 3l which are radially mounted on a flanged upper portion 32 ofthe shaft 22, the brushes being directed inwardly. This flanged portionforms a cup which is, during the operation of the apparatus, filled withcoating compound by the gear pump to a level sufcient to provide anadequate supply of coating material to the brushes 3I The brushes, whichare set in recesses 33 formed in the flanged portion 32, are held inplace by set screws 34 associated therewith. As may be seen in Figs. 2and 3, segmental notches 35 are formed in the hanged portion 32 of theshaft 22 adjacent the brushes 3| and these notches permit'unusedcompound to ow into an annular recess 36 which is formed in the hous-Ving II. A portion of this recess 36 communicates with the cavity I3, asmay be seen in Fig.

3, thus permitting the coating compound to return thereto. lI he depthof the notches 35 is selected to permit the coating compound to fill theflanged portion 32 of the shaft 22 to a sufficient height to provide anadequate supply of coating material for the brushes 3 I.

In the operation of this apparatus, the power shaft 26 is actuated torotate the gears I4 and I 5 causing thereby, as hereinbefore explained,coating compound to be pumped from the reservoir I3 to the brushes 3l.At the same time, rotation of the gear Il causes the brushes 3| torotate about the axis of the supporting shaft 22. In practice, the gearpump is preferably operated to circulate coating material for asuilioient time at the beginning of each operation to agitata thecoating compound to obtain a uniform dispersion of the particlesthereof, a carbon suspension in water, such as iAquadag, beingordinarily employed with this apparatus.

After the coating compound has been properly prepared, one end of aresistor 31, which is to be coated, may be inserted through an aperture38 formed in the center of a funnel-shaped plate 39 which is fitted inthe top of a cylindrical cover 4U, the lower portion of which ispositioned in the annular recess 36. This cover prevents coatingcompound from escaping during the operation of the device. The depth towhich the resistor may be inserted is controlled by an adjustable stopmember SI which is mounted on a cross member 42 fixed to the interior ofthe flanged portion 32 of the shaft 22 by a pair of bolts 43. Thefunnel-shaped plate 39 is employed so that any excess coating materialwhich might be removed from the coating apparatus 'as the resistor iswithdrawn therefrom will be ordinarily returned to the apparatus. Therotating brushes apply a uniform coating over the lower portion of theresistors, the stop member 4I being adjusted to present the desiredportion of each resistor to the brushes. After one end of the resistorhas been coated, the resistor may be inverted and a similar coatingapplied to the other end.

While but one embodiment of this invention has been shown and described,it will be understood that many changes and modifications may positionof an article with respect to said brush.

be made therein without departing from the spirit or scope of thepresent invention.

What is claimed is:

1. An apparatus for applying a coating to a selected portion of a,cylindrical article comprising a housing, a pair of intermeshing spurgears positloned in said housing, a power shaft for supporting androtating one of said gears, a hollow shaft for supporting the other ofsaid gears, a tank formed in said housing and so disposed that a portionof the peripheries of each of said gears extends therein, said housinghaving a passage for conducting the material from the gears to saidhollow shaft, said gears being rotated to pump coating material fromsaid tank and to force said material up said hollow shaft, and a brushmounted on said hollow shaft so as to be supplied with coating materialas coating compound is pumped through said shaft.

2. An apparatus for applying a coating to a selected portion of acylindrical article comprising a housing, a pair of intermeshing spurgears positioned in said housing, a power shaft for supporting androtating onev of saidgears, a hollow shaft for supporting the other ofsaid gears, a tank formed in said housing and so disposed that a portionof the peripheries of each of said gears extends therein, said housinghaving a passage 3. An apparatus for applying a coating to a selectedportion of a cylindrical article comprising a housing, a pair ofintermeshing spur gears positioned in said housing, a power shaft forsupporting and rotating one of said gears, a hollow shaft for supportingthe other of said gears, a tank formed in said housing and so disposedthat a portion of the peripheries of each of said gears extends therein,said housing having a passage for conducting the material from the gearsto said hollow shaft, said gears being rotated to pump coating materialfrom said tank and to force said material up said hollow shaft, a brushmounted on said hollow shaft so as to be supplied with coating materialas coating compound is pumped through said shaft, and means forreturning coating material to said tank.

4. An apparatus for applying acoating to a selected portion of acylindrical article comprising a housing, a pair of intenneshing spurgears positioned in saidv housing', a power shaft for supporting androtating one of said gears, a hollow shaft for supporting the other ofsaid gears, a tank formed in said housing and so disposed that a portionof the peripheries of each of said gears extends therein, said housinghaving a passage for conducting the material from the gears to saidhollow shaft, said gears being rotated to pump coating material fromsaid tank and to force said material up said hollow shaft, and a brushmounted on said hollow shaft so as to be supplied with coating materialas coating compound is pumped through said shaft, an annular channelbeing formed in said housing for returning coating material to saidtank.

5. An apparatus for applying a coating to a selected portion of a,cylindrical article comprising a housing, a pair of intermeshing spurgears ,positioned in said housing, a power shaft for supporting androtating one of said gears, a hollow shaft for supporting the other ofsaid gears, a tank formed in said housing and so disposed that a portionof the peripheries of each of said gears extends therein. said gearsbeing rotated to pump coating material from said tank and to force saidmaterial along a, channel formed in said housing communicating with saidhollow shaft and up said hollow shaft. and a brush mounted on saidhollow shaft so as to be supplied with coating material as coatingcompound is pumped through said shaft.

6. An apparatus for applying a coating to a selected portion of acylindrical article comprising a housing, a pair of intermeshing spurgears positioned in said housing, a power shaft for supporting androtating one of said gears, a hollow shaft for supporting the other ofsaid gears, a tank formed in said housing and so disposed that a portionof the peripheries of each of said gears extends therein, said gearsbeing rotated to pump coating material from said tank and to force saidmaterial along a channel formed in said housing communicating with saidhollow shaft and up said hollow shaft, and a brush mounted on saidhollow shaft so as to be supplied with coating material as-coatingcompound is pumped through said shaft, an annular channel being formedin said housing for returning coating material to said tank.

7. A coating apparatus comprising a hollow vertical shaft, a cup-shapedmember at the upper end thereof, a brush mounted on said cupshapedmember and directed inwardly, a reservoir for coating compound, andmeans for causing said compound to flow upwardly through said hollowshaft and into said cup-shaped member to maintain a predetermined levelof said compound at the brush.

8. A coating apparatus comprising a hollow vertical shaft, a cup-shapedmember at the upper end thereof, a brush mounted on said cup-shapedmember and directed inwardly, a reservoir for coating compound, meansfor causing said compound to flow upwardly through said hollow shaftinto said cup-shaped member to maintain a predetermined level of saidcompound at the brush, and means for returning said compound to saidreservoir.

9. A coating apparatus comprising a hollow vertical shaft, a cup-shapedmember at the upper end thereof, a brush mounted on said cup-shapedmember and directed inwardly, a reservoir for coating compound, andmeans for agitating said compound in said reservoir and for causing saidcompound to flow upwardly through said hollow shaft into said cup-shapedmember to maintain a predetermined level of said compound at the brush.

10. A coating apparatus comprising a hollow vertical shaft, a cup-shapedmember at the upper end thereof, a brush mounted on said cup-shapedmember and directed inwardly, a reservoir for coating compound,means'for agitating said compound in said reservoir and for causing saidcompound to ow upwardly through said hollow shaft into said cup-shapedmember to maintain a predetermined level of said compound at the brush,and means for returning said compound to said reservoir. v

11. .An apparatus for applying a coating to a selected portion of acylindrical article comprisl ing a housing, a pair of intermeshing gearscooperating with said housing to form a pump, a hollow shaft associatedwith one of said gears, a tank communicating with a portion of saidgears, means for conducting the Ydischarge from the pump to said hollowshaft, a driving connection to one of said gears for rotating said gearsand pumping said material from said tank and forcing it up the hollowshaft, and a brush mounted on said hollow shaft so as to be suppliedwith coating material as said material is pumped through the shaft.

12. An apparatus for pplying a coating to a selectedportion of acyiandrical article comprising a housing, a pair o intermeshing gearscooperating with said housing to form a pump, a hollow-shaft associatedwith one ofsaid gears, a tank communicating with a portion of saidgears, .means for conducting the discharge from the pump to said hollowshaft, a driving connection to one of said gears for rotating said gearsand pumping said material from said tank and forcing it up the hollowshaft, a brush mounted on said hollow shaft so as to be supplied withcoating material as said material is pumped through the shaft, and meansfor returning said coating material to said tank.

13. An apparatus for applying a coating to a selected portion of acylindrical article comprising a housing, a pair of intermeshing gearscooperating with said housing to form a pump, a hollow shaft associatedwith one of said gears. a tank communicating with a portion of saidgears, means for conducting the discharge from the pumpto said hollowshaft, a driving connection to one of said gears for rotating said gearsand pumping said material from said tank and forcing it up the hollowshaft, a brush mounted on said hollow shaft so as to be supplied withcoating material as said material is pumped through the shaft, and meansfor positioning an article with respect to said brush.

EVERETI J. SHAW.

